Re: [PATCH] brk: COMPAT_BRK: fix detection of randomized brk (was Re:[regression v2.6.38] Re: [PATCH v2] brk: fix min_brk lower bound computation forCOMPAT_BRK)

[Geert Uytterhoeven]

On Wed, Apr 6, 2011 at 22:38, Jiri Kosina <jkosina@xxxxxxx> wrote:
> From: Jiri Kosina <jkosina@xxxxxxx>
> Subject: brk: COMPAT_BRK: fix detection of randomized brk
>
> 5520e89 ("brk: fix min_brk lower bound computation for COMPAT_BRK")
> tried to get the whole logic of brk randomization for legacy (libc5-based)
> applications finally right.
>
> It turns out that the way to detect whether brk has actually been randomized in
> the end or not introduced by that patch still doesn't work for those binaries,
> as reported by Geert.
>
> I don't like it, but currently see no better option than a bit flag in
> task_struct to catch the CONFIG_COMPAT_BRK && randomize_va_space == 2
> case.
>
> Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
> Tested-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> ---
>
> I am not really happy about introducing the bit flag, but I currently
> don't see another option. And it's only for the legacy CONFIG_COMPAT_BRK
> case anyway.
>
> Andrew, Ingo, any opinions/objections?
>
> If not -- Andrew, I guess this should go into current -rc still.

And in 2.6.38-stable.

Does anyone still have libc5 binaries for i386?

Gr{oetje,eeting}s,

            Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
             Â Â -- Linus Torvalds
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